Newfoundland

(I have read that a Newf appeared on a Newfoundland postage stamp in 1887, but have not been able to find any images of that stamp, assuming what I read was correct.)

The bottom stamp above includes an image of King George VI, grandfather of the current British monarch King Charles III. The date just above his portrait is 12 May 1937, the day of his coronation as king.

Canada

This stamp was part of a 4-stamp set, issued in 1988, which also included the Tahltan Bear Dog,
the Nova Scotia Duck Tolling Retriever, and the Canadian Eskimo Dog in addition to the Newf.

St Pierre and Miquelon

(These two small islands, although fewer than 15 miles off the
southern coast of Newfoundland and Labrador, are French territory.)

Monaco

Central African Republic